U.S. Pat. No. 3,451,988 describes a polymerization catalyst and a process for polymerizing vinyl compounds therewith that utilizes hydrocarbyl lithium or magnesium compounds together with a bifunctional Lewis base which is described as including tertiary diamines in which the nitrogen atoms in the diamines are bridged by 1-4 carbon atoms. Although the tetramethylethylene diamine (TMEDA) appears to be the preferred diamine since it is used more often in the examples, R.sub.2 N-A-OR, wherein A includes alkylene groups, is also indicated as suitable.
However, the highest 1,2 contents of polybutadiene reported for TMEDA are the 87.5% and 89% reported in Col. 16. The highest 1,2 content reported in the patent is the 95% reported for tetrahydrofuran (also in Col. 16), but this is associated with a conversion or yield of only 33%. Moreover, with the preferred TMEDA there is subsequent methylation as described in Col. 15 of the patent.
Example 19 (Col. 20) is the only section of the patent in which a compound of the formula R.sub.2 N-A-OR is shown in use. In this example the compound (CH.sub.3).sub.2 NCH.sub.2 CH.sub.2 OCH.sub.3 is used. However the maximum 1,2 content is reported as 83% and the maximum conversion of 96% is given.